Checked the dwell and set it to 32.5 degrees which is what the Chilton's book says to set it to

Set the timing to 4 notches advanced. I'm not sure if each notch is a degree or 2. Any more advance causes backfire when I gun it (WHY?!?!?!?!) which is strange because it didn't do that before when I had it around 8 notches advanced. I plugged the vacuum advance when I did this.

I then checked the mix and plugged the vacuum nipple and timing advance nipple. Set the mix (best is still 1/4 out which is still puzzling). And it runs pretty well now.

The duct tape was a rudimentary vacuum port plug. Now I just use a rubber hose plugged with a screw.

I set the idle at 750 or 700. It is supposed to be 700 according to the sticker on top of the radiator shroud.

TO BE CLEAR... there is NO vacuum advance when the car is idling. it engages at around 1000 rpm while my idle is et at 700 or 750.

It's a manual trans car. 3 speed on the column with what I believe to be a 3.23 open diff.

I'll make another vid tomorrow when it's light out and show you guys how well it runs now. I'll also go over the dwell setting, rpm (on the engine analyzer, not on my little tach), carb mix, firing order, etc...

Snowman,If you want to try another carb, then send me a PM and I'll send you one. I have my original monojet, rebuilt, that worked great before we began our build (you can buy it, try it, or send it back depending on how it works out).

Removing the head is a great idea if you have the time and the money to go over the head. But if you are concerned about a mechanical internal component issue, then I would recommend a compression test and cylinder leakage test when the engine is cold and again when the engine is hot. The tests are cheaper than head work (especially if all of your problem is either fuel delivery or ignition related.)

Good luck

p.s. - think HEI

_________________________
If at first you don't succeed,then read the directions and try again.

'Ported' vaccuum advance is a product of the emmission laws, before the later '60s all vaccuum advance was full manifold vaccuum, either taken from the intake manifold or a carb port on the engine side of the butterfly.

The ported vaccuum is to defeat the vaccuum advance at idle, this, along with retarding the initial mechanical timing was supposed to lower the combustion temperatures, thus lowering NOX production.

For those from California that are old enough to remember the 'NOX Device' mandate for pre '66 cars when the smog checks started (this entailed disconnecting and plugging the vaccuum advance, retarding the timing, and putting a 'NOX' decal on the air cleaner) you know about the crappy running, overheating, and other problems this caused. The mod usually lasted long enough for an inspection then was put back to normal by the owner.

That being said... Snowman, if you are not going to fix your curb idle solenoid, you can rig a throttle stop the same height as the solenoid would be when extended, then your butterfly will be correctly aligned in the venturi (after backing off your curb idle screw and setting it correctly of course) then your mixture screw should be back to normal function.

I am a believer in full manifold vaccuum advance and running as much initial advance (like 10-12 degrees) as makes the engine happy, however, the smog carbs are jetted and calibrated for ported vaccuum so that is what you should probably do.

I have been working on cars for over 50 years, all I can say is this is what has worked for me.

Vanherk1I'll try to get a vacuum gauge from autozone. I'm hoping they loan them out but I might have to buy one.

JimWI'll try to see if autozone has a cylinder compression tester also because the one my dad has doesn't fit into my spark plug threads.Now that I think about it, I have to start driving to school in a month and I still need to fix my glass channels, weld in a replacement strip of metal for a rusted through part in the back channel, clean and primer, reseal, and put the windshield and back glass in.I'll keep working on my cab but if all else fails, I'll PM you. I don't want to waste your time

TimI'll try to rig a idle solenoid setup. I just want to see if it overruns when I get all of my settings correct

NOW FOR MY FINDINGS...I just went out and I must admit, I feel retarded. It turns out the PCV hose that goes into the middle runner of the intake manifold didn't seal all the way around (even though I had a tightened clamp on it) so I just put a rubber suction cup upside down on it and it sealed off completely. The other problem was the vacuum nipple (not the timing advance nipple), wasn't sealed off completely either. I used a screw inside of the rubber vacuum hose which I thought would seal it off. I did a test (put my mouth on it sucked, and see if it would hold on my tongue) and it turns out it didn't hold hardly anything. I just took out the screw and clamped it closed. So now no vacuum leaks!

I also took out the coil and cleaned off the dirt and grime and whatnot to make sure it wasn't grounding out. It didn't do much

I then set the advance to about 8 degrees advanced. The best mix is still 1/4 turn out though. It will now idle relatively steadily at about like 400 or 450. It still rocks a bit though every few seconds WCHIH IS REALLY ANNOYING. It just seems like it just doesn't fire for a split second every few seconds and just sends a vibration through the car. And it does this from 450rpm all the way through 1000rpm

I'll also try to post a youtube video of my progress, how it runs, and what's happening and what I've done.

I know I told you guys I'd do it yesterday but I've had school and driving school which is 9 hours out of my day so sorry about that.

Something else I'm also somewhat concerned about is a fair amount of white smoke comes out of my PCV valve on the front of the engine coming out of the valve cover. Is that burning oil or is that normal?

The white smoke is condensation steaming off. That stuff will accumulate in your motor if it does not get hot enough to steam out. It can cause corrosion and your oil to break down. Excessive idling and multiple cold starts will make it worse. You will be fine once it gets driven regular.

The other thing is that even after all my discoveries, it still backfires when I floor it. It is set at factory dwell, 8 degrees advanced, and the mix is still pretty good. But when I floor it, it sputters and either dies or it backfires through the carb. I can't understand why it would do this because it didn't do this before I adjusted the dwell, timing, and mix. I guess I have to just play with the settings? or is there a specific reason for it doing that?

The stumble/backfire on hard acceleration is caused by not enough accelerator pump "shot". In other words on hard acceleration the engine gets a gulp of air before it gets fuel. This results in a lean condition and the engine will stumble or backfire. The accelerator pump is suppose to supply extra fuel on hard acceleration to eliminate the lean condition.

With the engine SHUT OFF, look down into the carb throat then open the throttle quickly. You should see a solid squirt of fuel.Sometimes you can adjust the carb linkage to increase the pump "shot".

If you idle it down too low, you will not have sufficient oil pressure. Without having a oil pressure gauge to know, you need to get it up to 550 to 600.

You capped off the vacuum source on the intake manifold for the PCV system and now the engine smokes. Connect the dots.

That rubber hose on the front, side of the valve cover looks short, but it should have connected into the carb air cleaner. Is that not correct?

At idle the PCV system should have a slight vacuum on that hose, drawing fresh, filtered air from the carb air cleaner. Air enters the engine through that hose, collects the crankcase fumes that you saw, goes through the PCV valve into the intake manifold and the engine burns the fumes.

If the PCV hose is bad, replace the hose.

You say it idles best when the mixture screw is 1/4 turn out. What exactly happens when you turn the screw out an additional 1/4 turn?? What exactly happens when you add another 1/4 or 1/2 turn to that and it is at one full turn out????

You capped off the vacuum source on the intake manifold for the PCV system and now the engine smokes. Connect the dots.

That rubber hose on the front, side of the valve cover looks short, but it should have connected into the carb air cleaner. Is that not correct?

At idle the PCV system should have a slight vacuum on that hose, drawing fresh, filtered air from the carb air cleaner. Air enters the engine through that hose, collects the crankcase fumes that you saw, goes through the PCV valve into the intake manifold and the engine burns the fumes.

If the PCV hose is bad, replace the hose.

You say it idles best when the mixture screw is 1/4 turn out. What exactly happens when you turn the screw out an additional 1/4 turn?? What exactly happens when you add another 1/4 or 1/2 turn to that and it is at one full turn out????

Alright well why would it matter if the valve cover has vacuum if it is vented into the air cleaner assembly (where it would have slight vacuum anyway)?

It gets too rich when I turn it out and the engine slows (and dies if I turn it out more). If I turn it in, the engine leans and almost dies (unless I turn it in all the way and then it either runs awfully or dies).

'Alright well why would it matter if the valve cover has vacuum if it is vented into the air cleaner assembly (where it would have slight vacuum anyway)?'

Snowman, It is becoming apparent that you are not familiar with the way all the systems work and interact with each other, and are not willing to take the time to learn.

The PVC (Positive Crankcase Ventilation) system, takes filtered air from the air cleaner (the larger hose), which is drawn thru' the engine and regulated by the PCV valve, into the intake manifold (the smaller hose), or base of the carb in some applications, thus purging the oil and combustion bypass fumes into the intake and burning them in the engine, thus eliminating the blow-by being vented into the atmosphere.

This process is engineered by the auto manufacturer, regulated by the PVC valve, and the carburetor is calibrated to take this extra air/fume flow into consideration. Just removing the hoses and plugging them, without realizing the effect, doesn't accomplish your goal.

The same goes with the carburetor. The anti-dieseling solenoid was put there because in order for the engine to pass the pollution standards the compromises needed (retarded timing and leaner fuel/air mixture) caused the run-on when the engine was shut off. So this solenoid, which when energized, positions holds the butterfly in the correct configuration for normal operation, was incorporated to shut the throttle plate (butterfly) completely allowing the engine to die in a dignified manner without bucking and snorting when the ignition was turned off.

By just removing it, or allowing it to stay in the non-energized position, you don't have a stop for the idle speed screw to properly locate, which in turn is more than likely responsible for your mixture screw adjustment problems.

You will not cure the run-on without fixing everything back to factory stock, or getting another model carburetor that you can work with. I have tried redoing these carbs, it is not worth the trouble.

If it ran smoothly before you fixed it, there is probably nothing major wrong that you cannot figure out. Just go step-by-step on what you did and it will come to you.

Please read thru this post a couple of times before thinking I am being a jerk, I'm just trying to help.

He has not mentioned any dieseling or run-on since the very first post.The videos are not great, but I cannot see that it ever had one. It's a '69 and the only emission system visible is a PCV system.I don't recall any '60s engines with idle solenoids other than small displacement engines with Air Conditioners. They operated only when the AC was on to keep the engine from stalling at stop signals because of the then high compressor loads..

Idle solenoids were common in the late '70s when the engines had multiple EPA mandated emission systems and brand new engines couldn't run without one.

This discussion has been going on since June and is spread out among several topics. If you want to get the big picture do a search for topics by snowman4839, read all the posts and maybe you can come up with an answer to his dilemma.

Titen - I am VERY willing to learn. I wasn't trying to say that you're a jerk, I'm just asking a simple question. I'm not very familiar with PCV, I know that it is the pressure that slips past the pistons that needs to be vented out of the crankcase. Hence crankcase ventilation. I'm sorry if I came off rude.

RichardJ - Yes you're right. I haven't mentioned my dieseling since the first post because when I've had my mixes set well, it caused little to none. I'm thinking it was because of the air/vacuum leaks. But I should have fixed that. The engine originally did have an idle solenoid however but there's more about it in my video.

Quote:

His dilemma is rather obvious, and encouraging his "eagerness to earn" is called "enabling".

Well I'm SORRY if my attempts to learn are aggravating you. I just want to speak to people who know about these types of engines and while my questions may sometimes be elementary, the few sentences that you guys type give me a thousand ideas.

You just need another carb, so you can adjust the mixture screw.Turning the mixture screw more than 1/4 turn out & the engine will die,,,your carb is messed up.Get another one & try it out.Go to a junk yard & find one,ask members here if they have one for sale,borrow,, etc.

That idle solenoid may have been on the car, but it is hardle likely that it was original. Look on the Walker Products link you posted, pdf page 17, Rochester 1-ME,1-MV. Part #1 is the solenoid, #2 is the solenoid spring and straight to the left is a threaded hole in the carb body.

Here is a picture I found, of one with an electric choke just above the solenoid. That is how original solenoids were mounted.[img]http://67-72chevytrucks.com/vboard/attachment.php?attachmentid=523294&stc=1&d=1260657481[/img]( Sorry picture won't load. Must be protected )

What is wrong with the carb you have?? Good question.

Everything you have read about adjusting the carb mixture screw needle, said to lightly seat or turn the needle until it lightly bottoms and then back out 1 1/2 turns or some number. The important word here is lightly.The carb body is very soft. If the needle is seated too many times, it can damage the seat. If the needle is seated too tightly, it can damage the seat. If the needle spring prevents you from feeling when the needle has bottomed out, you can damage the seat.I fear "Mean Buzzen" is correct and that 1/4 turn is saying the seat is badly damaged.

I would do one thing before I bought a new carb. Spray "Carb & Choke Cleaner", all around the intake manifold and carb base to make absolute certain there are no more vacuum leaks.I like carb cleaner much better than brake cleaner or starter fluid. It's not as messy, not as flammable, cheaper, and isn't as hard on paint.

Snowman,Good job! It sounds great. Sorry to hear about the tach/ dwell meter. We have all been there. Better it than you!

I think Titen is fine with you being on here, I am. He just is one ornery old cuss. (JK)

With the work you are learning lots. It is good to get a grasp on how the different systems work together, even on a old car like this. For a 15 year old, I am impressed.

Main thing is, when you start driving that car. You will be watched likea hawk, that car will stick out like a sore thumb compared to modern stuff (both good and bad). Cops will remember it. Be safe with it.That engine runs good, wait till you test drive it before getting any carb. I have lots of never to be used 1 bbl carbs.

Also be sure to look over all the brake lines on that 40+ year old car ( both metal and rubber ones) they will kill you or someone else. Tom

richardJ - Alright. I've been waiting to find the time to go to autozone and try to buy some type of solvent to test for intake leaks.By "seat", do you mean the end of the needle? or the threads that the needle screws into or what? If it is the latter, then I guess I would need to get a new throttle body in which case, I might as well get a new carb. If you mean the end of the needle then would understand the problem because I would've smashed the end of the needle and then it wouldn't make a complete seal.

Tom - Thanks. I'll definitely keep my wits about me when I first start driving. The cops in my city are notorious about profiling teens and blacks.I'll try to give the brake lines a look-see next time I get the chance.

I made another video on what I'm doing to adjust the carb but now that you guys mention that there's probably a problem with the mix screw seat, that sounds more like the problem. http://www.youtube.com/watch?v=-h3Y0rGEUSs

After the video, I blow out all of the passages with 120psi of compressed air, adjusted the metering rod all the way down, and then put the top of the carb and it started overflowing??? I'm confused as to why because I didn't touch the float besides pulling it out to work on everything else and put it back in. I got it to stop overflowing by bending it to where I'm pretty sure it doesn't even allow the needle to allow fuel in but why would it have done that? Could I have damaged the needle seat threads or something?

snowman - if there is any debris / dirt in the float needle seat, it will not seal.

If you do not have a GM manual for this engine / carb - you would save yourself a lot of headaches by getting one. It will show you how to measure / adjust the float height.

Kudos for digging in and working on this at the ripe old age of 15 - I was tearing apart quadrajets and working on small blocks when I was your age and I learned a lot but like you - often didn't have good instructions or know the proper processes and I managed to dork a few things up along the way.

If it were me at this point - I would be saving for a new carburetor for this motor - there are lots of options and your best bet is to buy a new replacement model that has good instructions and a good reputation for performance and reliability.

X2 - hopefully it will clean up with carb cleaner and the overflow problem will be over.

But that problem brings up some food for thought. Any car with a carb can have the 'overflow' problem - do you have a fire extinguisher in the garage? I'd even advise to keep one in the trunk, mounted of course, once you get it on the road. I'm sure that some/many/most of the guys helping you out on this forum have had a carb fire at some point. And the straight six GM with carb directly above the exhaust manifold is susceptable to a problem.

I'd hate to see you have a disaster, especially with that Buick - that is a GREAT car in GREAT shape - I love Buicks (I'm working on a '64 Wildcat presently.) I've been looking for a Skylark or Special, but none of them in Northeast look like yours.

T Lowe is right - drive like an adult and be safe, and do me a favor - get an extinguisher.

Be safe and think HEI!

_________________________
If at first you don't succeed,then read the directions and try again.

That's what I thought. I just rubbed off the end of the needle and put it back in and it stopped overflowing (but the float adjustment probably stopped the flow as well). I remember that happening a few times.

Don't worry, I'm quite experienced in carb fires. I've had one notably large one where I was actually freaked out enough to run and get the fire extinguisher. We keep one in our pantry which is about 7 steps from me standing next to the car to be in front of and takes about 5 seconds to get.

I've looked at the rebuild instructions and the exploded diagram is good enough for disassembly and reassembly. It's just that the directions for float and metering rod adjustment and whatnot are not very clear. I get the general idea of what to do to adjust it but the picture they provide to help you further isn't clear. I'll try to get a picture of it on here.

For those of you guys suggesting HEI. Don't worry. That's in my gameplan. I have a thread called "Snowman Turbo Build" or something that MBHD started in the turbo section which lists my projected mods. Why are you guys suggesting this so much? Does it just provide a more stable tune or more accurate and consistent spark or what?

I'm not going to buy another single barrel because I've also listed in that thread that I"m planning on getting an offy 5416 (4 barrel intake) and a 500cfm or 600cfm 4 barrel for my turbo setup. If it gets bad enough to where my Rottenchester monojet becomes unusable, then I'll just try to get the offy/4 barrel setup to work. It's just depressing to me because I wanted to keep all of the stock things on my car in working order in case I wanted to return it to stock. Now the carb is out I guess...

A better fire extinguisher (less messy) are the Halon type .They do not leave a corrosive chemicle behind that you need to clean up when used.

Halon type extinguishers cost more but a lot less mess.

The HEI is suggested so much because it is a better distributer than points.Creates a hotter spark,pretty much maintenance free,no crossfireing w/that large distributer cap,more water proof (when steam cleaning engine) etc.

When the points distributer shaft bushings & shaft wears,that will make your dwell change,dont have that problem with dwell change w/an HEI.

W/an HEI, you just get more consistant spark.

I run an HEI on my Syclone & so far run up yo 25 psi,w/no spark blowing out yet,but I do run an MSD 6 box,I am sure that helps.

I always ran .035-.040" gap & ran up to 22-23 psi,never missed a beat.It's not only till now I will close the plug gap to roughly .026",just because I will be spraying a lot of methanol & am increasing the boost pressure.

I have the gap now @ .030" injecting meth & running 23-24 psi & it has not missed yet,just want to play it safe.

Now onto the carb (again). I just completely removed the idle tube and it would still run as if it had the idle tube in there. I'm pretty sure gas is getting around the idle tube hole in the bottom of the fuel bowl instead of actually being pulled through the idle tube which is making it run wayyyy rich.

My dad's friend came over yesterday because he's going to reproduce a very unique emblem that goes on my dad's car but there were less than 500 originally badged and they don't make repros. I got to asking him about the carb and he cleared some stuff up for me and I was doing mostly everything right. I told him about my idle tube problem and he said that since he can use a machine shop (i'm not sure if he owns one or works at one or what), he'll produce another idle tube that fits snuggly into the orifice. Hopefully that'll seal it up and fix the idle mix problem. If that doesn't fix it, I'll just try to get a new idle mix screw.

I'm still confused as to what you mean by the seat? I replaced the NEEDLE seat, the needle, and needle seat seal because they came in the rebuild kit.

Just go get another carb.Tlowe offered you an assortment of carbs to you,probably for a good price. Quote:" I have lots of never to be used 1 bbl carbs"Post #60084

Another member here offered to send you a working carb.

Throw that junk carb to the side (& play w/that to your hearts content) & use a known working one.

Sometimes,a carb will just go to junk after a simple rebuild.Caused from a simple piece of debree stuck in a passage that just will not come out no matter how many times you carb dip it,blow it out w/compressed air,,believe me ,it happens.